You will want to make an itinerary, and stick to it closely! Don't try to pack too much fun into each day! Use your body as a guide. Are you at your best early in the day? Plan things early and then allow for a rest period afterwards. If you are like me, and need a good bit of time in the morning, plan your activities for the afternoon! Work with your body, not against it. Balance sight-seeing with rest periods. Balance is key!
Start packing about a month in advance. It seems extreme, but it can take hours and hours to pack just for yourself! If you are packing for a spouse, or an entire family, you will want and NEED a month!
Get a "Vacation" notebook. Give each person you are packing for TWO sheets of paper. Write things on the lists as they come to you well before you even pull out your suitecases. Save PAGE ONE for items you need to purchase (new sunscreen!).
Don't begin packing until you have a good window of time to work with, and you feel rested enough to do it. It's a more physical task than you would think, a lot of back and forth to dressers and closets.
Don't load the suitecase until you have everything laid out. Use your bed to make stacks of items: a stack of tee-shirts, a stack of shorts, two bathing suits, swimsuite cover-up, beach towel, flip flops, a stack of pajamas, a stack of underwear, a pile of sock, one or two pair of jeans, two pairs of sneakers, etc... once you have everyting on your list, THEN you can begin loading up the suitcase!
Depending on where you are going, you will need to decide how much spending money you will need to take, and in what form will you carry it? Cash, traveler's checks? It's also a good idea to have a credit card with a decent open balance to bring with you. You may decide ahead of time if you will keep the cash in the bank at home, use the credit card for all transactions, and then pay it off in full upon returning home. OR, if you use cash and take the credit card for TRUE emergencies (no, the adorable tankini in aquamarine is NOT an emergency!)
You will also need to make arrangements for any pets you have. Will you board them? Have a pet sitter come to the home? Have a house-sitter stay while you are gone? Each of these options cost money. You will need to budget and save accordingly.
Most of us women need to preen before laying on a beach (or pool) somewhere... plan and allow time to touch up your roots, hair cuts, waxing, mani-pedi. Obviously, most of this can be done yourself if you prefer to save money. I actually love these tasks because I find I get more and more excited with each step! The suspense is building every day since the day you decided to go!
While you are doing any of these activites, even making the lists, enjoy it! Appreciate that you are well enough to go away from home! Basque in the fact that you will have glorious uninterrupted time with the ones you love! Let each step be exciting, not a chore.